Control device, power receiving device, electronic apparatus, and power transmission system

Abstract

A control device includes a control portion that controls a power supply portion that supplies power to a load based on received power received by a power receiving portion from a power transmitting device. In the case where the power receiving portion, after receiving a signal having a first frequency and a first duty from the power transmitting device, receives a signal having a second frequency that is different from the first frequency or a signal having a second duty that is different from the first duty, the control portion specifies an issued command based on a length of a reception period of the signal having the second frequency or the signal having the second duty.

What is claimed is: 
     
       1. A control device used in a power receiving device that contactlessly receives power from a power transmitting device, the control device comprising:
 a control portion configured to:
 control a power supply portion that supplies power to a load based on received power received by a power receiving portion in the power receiving device from the power transmitting device; and 
 in a case where the power receiving portion, after receiving a first signal having a first frequency and a first duty from the power transmitting device, has received a second signal from the power transmitting device, the second signal having a second frequency that is different from the first frequency or having a second duty that is different from the first duty:
 in a case of having judged that a time length of a reception period during which the power receiving portion has received the second signal is a first length, specify that an issued communication data issued by the power transmitting device is first communication data; and 
 in a case of having judged that the time length of the reception period is a second length that is different from the first length, specify that the issued communication data is second communication data that is different from the first communication data. 
 
 
 
     
     
       2. The control device according to  claim 1 , wherein the second frequency is a frequency that is higher than the first frequency. 
     
     
       3. The control device according to  claim 1 , wherein the control portion measures a frequency in a given period before the reception period as a reference frequency, and measures the time length of the reception period based on the reference frequency. 
     
     
       4. The control device according to  claim 1 , further comprising an oscillator circuit that generates an oscillation signal,
 wherein the control portion is configured to measure the time length of the reception period based on the oscillation signal generated by the oscillator circuit. 
 
     
     
       5. A power receiving device comprising the control device according to  claim 1 . 
     
     
       6. An electronic apparatus comprising the control device according to  claim 1 . 
     
     
       7. A control device included in a power transmitting device that contactlessly transmits power to a power receiving device, the control device comprising:
 a control portion configured to:
 control a power transmission portion in the power transmitting device that transmits power to the power receiving device; 
 cause the power transmission portion to transmit a first signal having a first frequency and a first duty to the power receiving device during a time period having a first length, to issue a first communication data to the power receiving device; and 
 after causing the power transmission portion to transmit the first signal, cause the power transmission portion to transmit a second signal having a second frequency that is different from the first frequency or a second duty that is different from the first duty, during a time period having a second length that is different from the first length, to issue second communication data to the power receiving device. 
 
 
     
     
       8. The control device according to  claim 7 , wherein the control portion is configured to change the frequency or the duty at a given timing after the power receiving device has started load modulation. 
     
     
       9. A control device included in a power transmitting device that contactlessly transmits power to a power receiving device, the control device comprising:
 a control portion configured to:
 control a power transmission portion in the power transmitting device that transmits power to the power receiving device; 
 cause the power transmission portion to be driven at a first frequency and a first duty during a time period having a first length, to issue a first communication data to the power receiving device; and 
 after causing the power transmission portion to be driven at the first frequency and the first duty, cause the power transmission portion to be driven at a second frequency that is different from the first frequency or at a second duty that is different from the first duty, during a time period having a second length that is different from the first length, to issue second communication data to the power receiving device. 
 
 
     
     
       10. A contactless power transmission system comprising a power transmitting device and a power receiving device,
 wherein the power transmitting device is configured to:
 contactlessly transmit a first signal having a first frequency and a first duty to the power receiving device, and 
 in a case where the power receiving device is in communication with the power transmitting device, contactlessly transmit a second signal having a second frequency that is different from the first frequency or having a second duty that is different from the first duty during a period having a prescribed length, and 
 
 the power receiving device, after contactlessly receiving the first signal from the power transmitting device, is configured to:
 contactlessly receive the second signal from the power transmitting device, 
 in a case of having judged that a time length of a reception period during which the power receiving device has received the second signal is a first length, specify that an issued communication data issued by the power transmitting device is first communication data, and 
 in a case of having judged that the time length of the reception period is a second length that is different from the first length, specify that the issued communication data is second communication data that is different from the first communication data. 
 
 
     
     
       11. A control device used in a power receiving device that contactlessly receives power from a power transmitting device, the control device comprising:
 a processor configured to control a power supply that supplies power to a load based on received power, the received power being received by a power receiver in the power receiving device from the power transmitting device, the processor being programmed to:
 determine whether the power receiver has received a first signal having a first frequency and a first duty from the power transmitting device; 
 determine whether the power receiver has received a second signal from the power transmitting device, the second signal having a second frequency that is different from the first frequency or having a second duty that is different from the first duty; 
 determine a time length of a reception period during which the power receiver has received the second signal; 
 in a case of having determined that the time length of the reception period is a first length, specify that an issued communication data issued by the power transmitting device is first communication data; and 
 in a case of having determined that the time length of the reception period is a second length that is different from the first length, specify that the issued communication data is second communication data that is different from the first communication data.